This application generally relates to television signal processing systems and methods, and particularly relates to color frame processing systems and methods.
In many composite video signals, such as NTSC or PAL video signals, for example, color is provided by a color frame. The color frame is usually provided via a frame sequence, such as an odd-even sequence for an NTSC video signal. The color frame is needed to fully synchronize, or Genlock, one composite signal to another. Thus, a video processing circuit that is analyzing the composite video signal needs to identify the color frame sequence, as well as other timing characteristics.
Disclosed herein is a color frame identifier circuit that generates a pseudo-subcarrier signal and compares the pseudo-subcarrier signal to a sliced color burst of at least one selected line in a video frame over successive video frames. Based on this comparison, a processing circuit determines the color frame.